The present invention pertains generally to semiconductor lasers and more particularly to multiple heterojunction lasers. Early semiconductor lasers were constructed to produce lasing action in single p-n junctions of GaAs. These semiconductor lasers operated only at cryogenic temperatures and produced low output power in the plane of the junction. More recently, room temperature semiconductor lasers have been fabricated using double heterojunctions of high refractive index GaAs surrounded by low refractive index AlGaAs. Since optical gain occurs in the center GaAs layer, good optical confinement is obtained. However, the power output is limited since lasing occurs in the small volume of a single p-n junction. In addition, the beam produced by the double heterojunction laser is geometrically poor since it is planar and has large divergence due to diffraction from the narrow planar emitting junction. Moreover, the double heterojunction is constructed by growing several epitaxial layers. This method of fabrication leads to strains and microcracks which form regions of high absorption and limit the lifetime of the device. These imperfections can be avoided only by expensive and delicate fabrication methods.